Sen. Olympia Snowe (R-Maine) on Wednesday turned down a White House invitation to attend Thursday’s health care summit, calling their offer “inappropriate” since it broke their own rules for the event.

The White House called Snowe on Wednesday morning to ask her to come, but she declined because “the Republican leadership understood the rules of the summit, as established by the administration weeks ago, were that the Democratic and Republican leadership would select their own members to participate in the event,” Snowe spokesman John Gentzel said in a statement.

Gentzel said GOP leadership had “long since selected their team” of attendees so “it would have been inappropriate” for Snowe to accept the invitation.

“This is a summit between the leadership and the president, and she believes it is a critical opportunity for the respective leadership teams to convey their ideas directly with the president,” Gentzel said. Snowe, a moderate who was the lone GOP vote for the Finance Committee’s health care bill last year, assured the White House that she “will continue to play a leadership role” in the coming days and weeks.

A White House aide said President Barack Obama told both Snowe and Sen. Ron Wyden (D-Ore.) during individual meetings over the last year that, if he held a health care summit, he would invite them. Obama reached out to both this week after Senate leaders submitted their list of attendees and neither Senator was on the list.

Wyden accepted the invite and Snowe declined, “so we invited [Senate Minority Leader Mitch] McConnell and [House Minority Leader John] Boehner to agree on an additional guest to bring,” said the aide.

GOP leaders have yet to name their additional guest.